Comparative adsorption of nitrate ions on the polypyrrole and polyaniline from aqueous solution

The objective of this study was to compare the adsorption of nitrate ions using two conducting polymerspolypyrrole (PPy) and polyaniline (PANi)as adsorbents. The effects of different adsorption parameters including contact time, pH, temperature, initial concentration, adsorbent dosage, and presence of orthophosphate ions were investigated in batch experiments. Kinetic studies indicated that the adsorption process follow pseudo-second-order kinetic model. The Langmuir model fitted the experimental data much better than the Freundlich and Temkin models. The PANi showed higher adsorption capacity to nitrate ions than that of PPy. The adsorption of NO3- ions onto the PANi and PPy was spontaneous and exothermic.